Effects of PTEN Loss and Activated KRAS Overexpression on Mechanical Properties of Breast Epithelial Cells

Int J Mol Sci. 2018 May 30;19(6):1613. doi: 10.3390/ijms19061613.

Abstract

It has previously been shown that the simultaneous activation of PI3K (phosphatidylinositol 3-kinase) and Ras/MAPK (mitogen-activated protein kinases) pathways facilitate tumor growth despite only inducing cancer cell dormancy individually. Determining the impacts on cellular mechanics each pathway incites alone and in unison is critical to developing non-toxic cancer therapies for triple-negative breast cancers. PTEN (phosphatase and tensin homolog) knockout and activated KRAS (Kristen rat sarcoma viral oncogene homolog) overexpression in healthy MCF-10A human breast epithelial cells activated the PI3K and Ras/MAPK pathways, respectively. Cell stiffness and fluidity were simultaneously measured using atomic force microscopy. Results suggest that PTEN knockout reduced cell stiffness and increased cell fluidity independent of PI3K activation. Effects of activated KRAS overexpression on cell stiffness depends on rigidity of cell culture substrate. Activated KRAS overexpression also counteracts the effects of PTEN knockout.

Keywords: atomic force microscopy; cancer; cell mechanics.

MeSH terms

  • Actin Cytoskeleton / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Cell Proliferation / physiology
  • Drug Resistance, Neoplasm / genetics
  • Drug Resistance, Neoplasm / physiology
  • Epithelial Cells / metabolism*
  • Female
  • Humans
  • Mitogen-Activated Protein Kinases / genetics
  • Mitogen-Activated Protein Kinases / metabolism*
  • PTEN Phosphohydrolase / genetics
  • PTEN Phosphohydrolase / metabolism*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction / genetics
  • Signal Transduction / physiology
  • ras Proteins / genetics
  • ras Proteins / metabolism

Substances

  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • Mitogen-Activated Protein Kinases
  • PTEN Phosphohydrolase
  • PTEN protein, human
  • ras Proteins